Automated printing processes, in which a computer-controlled printer is used to print onto a printable medium, are now commonplace. Many different types of printers are known, including ink jet, laser, dot matrix, impact matrix, thermal transfer and daisywheel types. The printable medium may be a sheet of paper or card, cloth, or one or more labels. In the case of labels, it is common for a plurality of adhesive labels to be obtained on backing paper, which is then fed through the printer. The print itself may be alphanumeric characters, text, images, bar codes or pictures.
All the above media are readily utilised over a wide range of sizes. Among large scale media, for example, are advertising posters and decalcomania. Smaller scale media are used in the printing of packaging materials and labels. Very small labels are used for labelling electronic components and wiring. In all these cases, and especially with the printing of labels, it is critically important that the print be accurately positioned on the printable medium. Incorrectly positioned print looks slipshod and unprofessional, and, if taken to an extreme case, may result in some of the desired print actually missing the intended area. This results in text and/or pictures being cropped, resulting in the need to repeat the print job, which may be both costly and time consuming.
With some jobs, such as printing instructions on pharmaceutical containers, if the print misses the desired label area the consequences can be extremely serious. In such a case, the patient might only receive part of the instructions, and this could result in him taking an inappropriate course of treatment.
In the case of very small labels, such as those used for electronic components, the labels must be aligned very accurately if the text is to be properly positioned. If the text is not positioned properly, it can be very awkward to adjust the printer or computer software to rectify the error. Traditionally this ‘fine tuning’ has been achieved by the user printing onto a blank sheet of paper and then holding this up against the actual sheet of labels. He then measures in some way how much various blocks of information are out (usually top left, top right and bottom left) and enters these measurements into computer software which makes the appropriate adjustments to settings such as the top margin, left margin, horizontal pitch and vertical pitch. Alternatively the user might print directly onto a sheet of labels (or a sheet on which the outlines of labels have been marked) and would then measure manually the deviation of the print from the desired position. This information would then be entered into the software which would make the necessary adjustments.
The method described above relies to a great extent on trial and error. The measurement of the deviation of the print must be made manually, and this is both slow and prone to error. Multiple test printouts often have to be made before acceptably positioned print is obtained.
It is accordingly an object of the present invention to overcome or at least mitigate one or all of the problems noted above.